1. Field of the Invention
The invention concerns a mounting arrangement or device for carrying power conductors and instrument leads through the walls and barriers in nuclear reactor installations. More particularly, the mounting device provides a means for the penetration of the power conductor and instrument leads into a nuclear reactor pressure vessel.
2. Background of the Prior Art
In nuclear reactor installations, a controlled and self-perpetuating chain reaction is maintained in a limited and defined space. The radioactive elements and the radiation therefrom are inseparable components of such chain reactions. Protection of any biological matter is, therefore, necessary in the environment of a nuclear reactor. The intensity of the radiation generated and its localization, is reduced to the extent possible, to the area of activity of the self-perpetuating chain reaction. This is accomplished by means of a steel and concrete layer of the concrete vessel constructed surrounding the reactor for this purpose. The process of nuclear fission within the reactor vessel and its conversion to heat energy is under the surveillance of instruments during the entire operating period of the reactor. The instruments are monitored and controlled from outside the vessel.
Devices for electric conductors penetrating into and connecting the internal activated area, wherein the measuring and surveillance instruments are arranged with the unactivated area are known. These penetration devices are usually arranged in an orifice provided in the concrete jacket of the reactor vessel. The orifice is lined with an armor tube. The devices are designed so that the replacement of the concrete layer by the device does not result in an additional increase in radiation exposure outside the concrete vessel. This is achieved by equipping the penetration device with materials assuring an adequate reduction in radiation intensity. The materials intended for the shielding of radiation are laid out in the form of separate layers in a tubular housing and are equipped with electrical conductors extending through the entire housing and connecting the two spaces.
In a known device, the one end of the housing arranged on the inner wall of the housing is fastened with screws or bolts to the vessel wall flush with the plane of the wall.
Known penetration devices of this type have the disadvantage that they consist of relatively numerous special, individual parts. The need for specially manufactured parts unfavorably affects the cost of manufacturing. The repair work, elimination or replacement of these devices often necessary when these devices are damaged is associated with substantial complications. This is because maintenance work controlled from the outside cannot be easily performed on penetration devices of this type.